1. Field of the Invention
The present invention relates to compressed-gas breakers.
2. Background of the Invention
An example of a known compressed-gas breaker can be found in US-A-4,658,108. The known breaker has a pressure space of constant volume, enclosed by the movable member of its two contact members. In breaking, this pressure space is supplied with arc-generated compressed gas for blowing out the arc when the current to be interrupted approaches zero. Although this results in a considerable saving in drive energy in comparison with a compressed-gas breaker in which the compressed gas used for blowing out the arc is generated only by a piston-cylinder compression device operated by a breaker drive, with such a breaker any required increase in the contact-parting speed could previously only be achieved by a considerable increase in the drive energy.
It is known from DE-C2-2,946,929 to increase the parting speed of the power contacts of a compressed-gas breaker by the power contact of the movable contact member being operated by means of a lever arrangement operated by the breaker drive or by a rack-and-pinion gear. However, in this case the quenching geometry of the contact arrangement of the compressed-gas breaker is changed and consequently its quenching capability is affected. In addition, the power contact of the movable contact member in this switch closes the flow outlet of the compression space of a piston-cylinder compression device operated by the breaker drive during breaking for virtually the entire compression phase. Therefore, this breaker requires a comparatively high drive energy.